Thanks for you interest in the Percolator. To answer your question, it’s won’t damage anything in the amp if you use a 16 ohm speaker, but you won’t get the same wattage/volume level out of the Percolator. Also, I can’t guarantee how it will sound because I’ve actually never driven a 16 ohm speaker with the Percolator, but you are welcome to experiment.
-Brach